1. Field of the Invention
The present invention relates to an individual sheet overlapping mechanism for overlapping two or more individual sheets having different cutoffs (cutting lengths), a folding device, and a printing apparatus, and to an individual sheet overlapping method.
2. Description of the Related Art
Conventionally, an ink jet printing type newspaper production device has been proposed as a device for producing a newspaper form signature (see JP 2011-157168A). The newspaper production device disclosed in Patent Document 1 includes a paper feed unit that supplies a continuous paper, an ink jet printing unit capable of printing on both sides of the continuous paper, and a folding unit that cuts and folds the post-printing continuous paper. This folding unit is a rotary folding unit comprising a folding cylinder that includes a holding mechanism that holds paper on an outer peripheral surface of the folding cylinder and a folding blade mechanism that thrusts the held paper in an outwardly radial direction. Moreover, this folding unit is configured capable of executing a so-called collect run in which paper held by the holding mechanism is folded every plurality of rotations of the folding cylinder to produce the signature.
In an ink jet printing type newspaper production device as in the newspaper production device of Patent Document 1, contrary to in a conventional offset press, there is no need for a plate, hence there is no limit to the number of pages of different contents capable of being printed in a direction of continuity of one continuous paper. Therefore, due to the ink jet printing type newspaper production device, it is possible to print pages of required content in a predetermined order on the continuous paper, cut the printed continuous paper to form individual sheets, and overlap and fold these individual sheets, thereby producing a signature configured from a plurality of individual sheets having pages of different content printed thereon. In this way, the ink jet printing type newspaper production device can produce a signature of any number of pages provided there is one printing unit capable of printing on both sides of the continuous paper. Hence, the ink jet printing type newspaper production device has the advantage of being able to produce a newspaper at low cost and in a space-saving manner, without the need to increase the number of printing units corresponding to the number of pages as in a conventional offset press.